On Wed, Mar 01, 2023 at 05:38:15PM -0800, Stephen Boyd wrote:
To fully exercise common clk framework code in KUnit we need to associate 'struct device' pointers with 'struct device_node' pointers so that things like clk_get() can parse DT nodes for 'clocks' and so that clk providers can use DT to provide clks; the most common mode of operation for clk providers.
Adding support to KUnit so that it loads a DTB is fairly simple after commit b31297f04e86 ("um: Add devicetree support"). We can simply pass a pre-compiled deviectree blob (DTB) on the kunit.py commandline and UML will load it. The problem is that tests won't know that the commandline has been modified, nor that a DTB has been loaded. Take a different approach so that tests can skip if a DTB hasn't been loaded.
Reuse the Makefile logic from the OF unittests to build a DTB into the kernel. This DTB will be for the mythical machine "linux,kunit", i.e. the devicetree for the KUnit "board". In practice, it is a dtsi file that will gather includes for kunit tests that rely in part on a devicetree being loaded. The devicetree should only be loaded if CONFIG_OF_KUNIT=y. Make that a choice config parallel to the existing CONFIG_OF_UNITTEST so that only one devicetree can be loaded in the system at a time. Similarly, the kernel commandline option to load a DTB is ignored if CONFIG_OF_KUNIT is enabled so that only one DTB is loaded at a time.
Add a simple unit test to confirm that the DTB loading worked. Future tests will add to the kunit.dtsi file to include their specific test nodes.
Cc: Richard Weinberger richard@nod.at Cc: Anton Ivanov anton.ivanov@cambridgegreys.com Cc: Johannes Berg johannes@sipsolutions.net Cc: Vincent Whitchurch vincent.whitchurch@axis.com Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Signed-off-by: Stephen Boyd sboyd@kernel.org
arch/um/kernel/dtb.c | 29 +++++++++++++++-- drivers/of/Kconfig | 26 ++++++++++++++++ drivers/of/Makefile | 1 + drivers/of/kunit/.kunitconfig | 4 +++ drivers/of/kunit/Makefile | 4 +++ drivers/of/kunit/kunit.dtsi | 8 +++++ drivers/of/kunit/kunit.dtso | 4 +++ drivers/of/kunit/uml_dtb_test.c | 55 +++++++++++++++++++++++++++++++++ 8 files changed, 128 insertions(+), 3 deletions(-) create mode 100644 drivers/of/kunit/.kunitconfig create mode 100644 drivers/of/kunit/Makefile create mode 100644 drivers/of/kunit/kunit.dtsi create mode 100644 drivers/of/kunit/kunit.dtso create mode 100644 drivers/of/kunit/uml_dtb_test.c
diff --git a/arch/um/kernel/dtb.c b/arch/um/kernel/dtb.c index 484141b06938..ee63951b12df 100644 --- a/arch/um/kernel/dtb.c +++ b/arch/um/kernel/dtb.c @@ -15,9 +15,32 @@ void uml_dtb_init(void) long long size; void *area;
- area = uml_load_file(dtb, &size);
- if (!area)
return;
- if (IS_ENABLED(CONFIG_OF_KUNIT)) {
/** __dtbo_kunit_begin[] and __dtbo_kunit_end[] are magically* created by cmd_dt_S_dtbo in scripts/Makefile.lib from the* drivers/of/kunit/kunit.dtsi file.*/extern uint8_t __dtbo_kunit_begin[];extern uint8_t __dtbo_kunit_end[];size = __dtbo_kunit_end - __dtbo_kunit_begin;if (!size) {pr_warn("%s: kunit testcases is empty\n", __func__);return;}/* creating copy */area = memblock_alloc(size, 8);if (!area)return;memcpy(area, __dtbo_kunit_begin, size);- } else {
area = uml_load_file(dtb, &size);if (!area)return;- }
if (!early_init_dt_scan(area)) { pr_err("invalid DTB %s\n", dtb); diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 80b5fd44ab1c..1f968b6a3dde 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -12,6 +12,20 @@ menuconfig OF if OF +choice
No. This needs to be reworked such that a kernel rebuild is not needed to run different tests. I suspect that the overlay approach will do that for you.
- prompt "Devicetree Runtime Tests"
- default OF_UNITTEST
+config OF_KUNIT
- bool "Devicetree KUnit support" if KUNIT
- depends on UML
This is not a great dependency either...
Rob